Mass storage systems continue to provide increased storage capacities to satisfy user demands. Photo and movie storage, and photo and movie sharing are examples of applications that fuel the growth in demand for larger and larger storage systems.
A solution to these increasing demands is the use of arrays of multiple inexpensive disks. These arrays may be configured in ways that may provide redundancy and error recovery without any loss of data. These arrays may also be configured to increase read and write performance by allowing data to be read or written simultaneously to multiple disk drives. These arrays may also be configured to allow “hot-swapping” which allows a failed disk to be replaced without interrupting the storage services of the array. Multiple disk storage systems typically utilize a controller that shields the user or host system from the details of managing the storage array. The controller may make the storage array appear as one or more disk drives (or volumes). This is accomplished in spite of the fact that the data (or redundant data) for a particular volume may be spread across multiple disk drives.
To facilitate the development and deployment of these multiple disk storage systems, several specifications have been developed. Few of these specifications are promulgated by the Storage Bridge Bay Working Group, Inc. In particular, the Storage Bridge Bay Working Group, Inc. has promulgated the Storage Bridge Bay (SBB) Specification, Version 2.0, Jan. 28, 2008 available at www.sbbwg.org. This specification aims to define common mechanical, electrical, and internal interfaces between a storage enclosure and the electronics cards that give the system a function. The ultimate aim of the SBB specification is to allow multiple different controllers to be used in a single, standard compliant, chassis to change the “personality” of the storage array.